America celebrated its resilience this Sept. 11, but the looming specter of new attacks requires renewed vigilance. From energy assets to cyberterrorism, John Solomon explores a dozen potential threats—and our preparedness.

With solemn grandeur, Americans celebrated a decade of resilience and resolve since the terror attacks of Sept. 11, 2001. And while the celebration of the anniversary—the first since Osama bin Laden’s death—may have helped bring closure to some, it can’t obscure the looming threat of new attacks as the United States enters its second decade in the war against terror.

Al Qaeda‘s attacks a decade ago exposed what the 9/11 commission concluded was “failures of imagination” in the security posture of the United States, the inability to envision the tactics that a determined, crafty enemy might use against Americans.

After hundreds of billions of dollars spent on homeland security, America clearly is safer and more aware of the threats surrounding it. Likewise, the U.S. military, the CIA, and the FBI have thinned out much of al Qaeda’s leadership in recent years, diminishing its operational capacity through relentless drone strikes and captures.

The 10th anniversary of the 9/11 attacks was an obvious date for al Qaeda to strike, but other upcoming dates would provide symbolic significance for the terror group and its sympathizers.

But just as few imagined using jetliners as missiles before 9/11, today there are new and evolving threats to guard against. A Daily Beast review of recent intelligence warnings and federal safety assessments shows the United States isn’t fully prepared for some attacks on targets deemed to be high risk—from cyberterror to offshore energy assets.

“This array of threats underscores to me the key question posed by bin Laden’s death. Does his killing represent the beginning of the end of the ‘war on terrorism,’ or is it simply the end of the beginning?” says Clark Ervin, a terrorism expert at the Aspen Institute and the former inspector general of the Department of Homeland Security.

“It is, of course, a very good thing that there’s not been a major terror attack in the U.S. since 9/11. But it would as much a ‘failure of imagination’ to suggest that we cannot be attacked again as it was for pre-9/11 policymakers to assume that we would not be attacked ever.”

With little fanfare, FBI and Homeland Security officials have identified in recent bulletins several harrowing tactics that al Qaeda, its spinoff group in Yemen, or other affinity terrorists might use in coming months.

Gleaned from law-enforcement bulletins and terrorism experts, here are some of the threats, tactics, and players that Americans will have to be vigilant against at the dawn of the second decade of the war against terror.
1. Biochemical Attacks

An intelligence report this summer warned that al Qaeda in the Arabian Peninsula was seeking castor beans, the simple but deadly ingredient needed to make a quick and lethal dose of the poison ricin. One concern was that ricin might be used in a subway attack, combined with an explosion to disperse the deadly toxin through the closed tunnels of a subway system. This is a scenario the U.S. military has long feared, going back to the 1960s and 1970s, and the sarin gas attack in Japan’s subways in the 1990s showed its lethality.
2. Radiological Bombs

The so-called dirty bomb has been an obsession of U.S. intelligence and counterterrorism officials for years, dating to 2002, when the FBI suspected an Illinois man named Jose Padilla of plotting such an attack. Padilla was ultimately convicted of other crimes. Still, officials recognize it would be fairly easy for a terror group to collect radiological waste from hospital machines overseas and package it with an explosive.

FBI Director Robert Mueller once said in an interview that this was a scenario that kept him up at night. It’s a low-scale but tried-and-true approach in other countries, such as Israel and Afghanistan. But it would be new to the United States. And if unleashed in shopping malls, it could create the sort of panic that would shake consumer confidence in an already weak economy.

4. Vehicle Bombs

This is one of the oldest forms of terrorism, but it’s still a major threat. In the last few months alone, U.S. intelligence has picked up significant signs that al Qaeda and its allies have been plotting attacks with explosive-laden cars, trucks, and boats. The attack in June on a hotel in Afghanistan frequented by Westerners relied on a fertilizer bomb embedded in a vehicle similar to that used by Timothy McVeigh in 1995 in Oklahoma City. The Yemen arm of al Qaeda tried such an attack in Times Square less than two years ago, and threat information last week warned of a possible car or truck bomb targeting bridges and tunnels in New York or Washington.

5. Cyberterrorism

This may be one of our Achilles’ heels. In the last year, cyberattackers have disrupted or accessed some of the Pentagon’s most sensitive documents and computer systems while exposing private information of customers in the business world. Despite billions spent, the country still has relatively few defenses. A Government Accountability Office report last year warned that the U.S. government’s efforts to ward off a cyberattack suffered from “overlapping and uncoordinated responsibilities” and a lack of clarity about who is in charge. With the help of a state sponsor well versed in cyberwarfare, a terror group could shut down parts of the U.S. electric grid, cause havoc with financial trades, or disable or hack into sensitive government computer systems at great cost to American security.

6. Small Aircraft Loaded With Explosives

In the days immediately after 9/11, fighter jets roared through the American skies on constant patrol. But those are now a distant memory, and safeguards at rural and small airports are not the same as with major airliners and airports. U.S. officials have long worried about terrorists loading a small airplane with explosives and flying it into a major event with crowds, such as sporting events, concerts, amusement parks, or political debates.

7. Train Bombs

While Amtrak has beefed up security and resources since 9/11, the 7/7 attacks in Britain in 2005 showed how devastating and easy train bombs can be as a tool of terror and death. And unlike the U.S. airlines, trains have fewer security precautions and far more access points for terrorists. Just two years ago, authorities thwarted a suspected bombing plot aimed at New York’s subway trains.

8. Energy Assets

When Pakistani officials working with the CIA captured Younis al-Mauritani, al Qaeda’s No. 2, earlier this month, they were reminded anew that the terror network has plotted to blow up oil and energy assets ranging from nuclear-power plants and hydroelectric dams to oil-drilling rigs and tankers. Mauritani “was planning to target United States economic interests including gas [and] oil pipelines, power generating dams, and strike [oil tankers] through explosive laden speed boats in international waters,” the Pakistani Army reported. Documents found in bin Laden’s hideout also affirmed an interest in attacking offshore energy interests. Despite the repeated warning signs, a GAO expert in maritime safety told Congress last month that the government lacks a fully coordinated plan for stopping or responding to such an attack.

9. Al Qaeda in the Arabian Peninsula

This is considered the most dangerous of the regional arms of al Qaeda. Based in Yemen, the group is responsible for two of the biggest foiled attempts at terror attacks: a Nigerian man with a bomb sewn into his underwear who tried to blow up a commercial airliner to Detroit on Christmas Day 2009, and packages with powerful explosives in cargo bound for Chicago in late 2010.

10. Homegrown Terrorists

In the last year the Obama administration has placed a greater emphasis on preventing attacks from Americans inspired by al Qaeda’s English-language propaganda on the Internet. In June, John Brennan, the deputy national-security adviser for counterterrorism and homeland security, said his new plan was the “first counterterrorism strategy that focuses on the ability of al Qaeda and its network to inspire people in the United States to attack us from within.” One example was the November 2009 rampage of Army Maj. Nidal Malik Hasan at Fort Hood military base. Such small-arms attacks are less lethal than 9/11 by orders of magnitude but are also much harder to prevent—and rely on an alert citizenry. The Department of Homeland Security launched a campaign this year called “See Something, Say Something” to encourage Americans to alert law enforcement when they observe suspicious activity.

11. Symbolic Dates

The 10th anniversary of the 9/11 attacks was an obvious date for al Qaeda to strike, but other upcoming dates would provide symbolic significance for the terror group and its sympathizers. They include Oct. 7, the 10th anniversary of the invasion of Afghanistan; Dec. 9, the 10th anniversary of the fall of the Taliban government to coalition forces; and May 2, the one-year anniversary of bin Laden’s death.

12. Unfinished Business

Al Qaeda has a patience and determination to strike the same targets, a point made clear when the terror group targeted the World Trade Center in New York in 2001 after a less spectacular attack in 1993. There is evidence that al Qaeda has had its eyes on Los Angeles (a target of the failed millennium bomb plot of 1999 and recently mentioned in documents recovered from bin Laden’s hideout), Las Vegas (which the 9/11 hijackers once visited), the Sears Tower in Chicago, and the U.S. Capitol building in Washington (supposed to be the target of the 9/11 jetliner that crashed in Pennsylvania).